The graph has two obvious and conspicuous features. First, a steady increase of carbon dioxide with time, beginning at 315 parts per million in 1958 and reaching 385 parts per million in 2008. Second, a regular wiggle showing a yearly cycle of growth and decline of carbon dioxide levels. The maximum happens each year in the Northern Hemisphere spring, the minimum in the Northern Hemisphere fall. The difference between maximum and minimum each year is about six parts per million.

Keeling was a meticulous observer. The accuracy of his measurements has never been challenged, and many other observers have confirmed his results. In the 1970s he extended his observations from Mauna Loa, at latitude 20 north, to eight other stations at various latitudes, from the South Pole at latitude 90 south to Point Barrow on the Arctic coast of Alaska at latitude 71 north. At every latitude there is the same steady growth of carbon dioxide levels, but the size of the annual wiggle varies strongly with latitude. The wiggle is largest at Point Barrow where the difference between maximum and minimum is about fifteen parts per million. At Kerguelen, a Pacific island at latitude 29 south, the wiggle vanishes. At the South Pole the difference between maximum and minimum is about two parts per million, with the maximum in Southern Hemisphere spring.

The only plausible explanation of the annual wiggle and its variation with latitude is that it is due to the seasonal growth and decay of annual vegetation, especially deciduous forests, in temperate latitudes north and south. The asymmetry of the wiggle between north and south is caused by the fact that the Northern Hemisphere has most of the land area and most of the deciduous forests. The wiggle is giving us a direct measurement of the quantity of carbon that is absorbed from the atmosphere each summer north and south by growing vegetation, and returned each winter to the atmosphere by dying and decaying vegetation.

The quantity is large, as we see directly from the Point Barrow measurements. The wiggle at Point Barrow shows that the net growth of vegetation in the Northern Hemisphere summer absorbs about 4 percent of the total carbon dioxide in the high-latitude atmosphere each year. The total absorption must be larger than the net growth, because the vegetation continues to respire during the summer, and the net growth is equal to total absorption minus respiration. The tropical forests at low latitudes are also absorbing and respiring a large quantity of carbon dioxide, which does not vary much with the season and does not contribute much to the annual wiggle.

When we put together the evidence from the wiggles and the distribution of vegetation over the earth, it turns out that about 8 percent of the carbon dioxide in the atmosphere is absorbed by vegetation and returned to the atmosphere every year. This means that the average lifetime of a molecule of carbon dioxide in the atmosphere, before it is captured by vegetation and afterward released, is about twelve years. This fact, that the exchange of carbon between atmosphere and vegetation is rapid, is of fundamental importance to the long-range future of global warming, as will become clear in what follows. Neither of the books under review mentions it.

Before making his assertion:

At this point I return to the Keeling graph, which demonstrates the strong coupling between atmosphere and plants. The wiggles in the graph show us that every carbon dioxide molecule in the atmosphere is incorporated in a plant within a time of the order of twelve years. Therefore, if we can control what the plants do with the carbon, the fate of the carbon in the atmosphere is in our hands. That is what Nordhaus meant when he mentioned "genetically engineered carbon-eating trees" as a low-cost backstop to global warming. The science and technology of genetic engineering are not yet ripe for large-scale use. We do not understand the language of the genome well enough to read and write it fluently. But the science is advancing rapidly, and the technology of reading and writing genomes is advancing even more rapidly. I consider it likely that we shall have "genetically engineered carbon-eating trees" within twenty years, and almost certainly within fifty years.

Carbon-eating trees could convert most of the carbon that they absorb from the atmosphere into some chemically stable form and bury it underground. Or they could convert the carbon into liquid fuels and other useful chemicals. Biotechnology is enormously powerful, capable of burying or transforming any molecule of carbon dioxide that comes into its grasp. Keeling's wiggles prove that a big fraction of the carbon dioxide in the atmosphere comes within the grasp of biotechnology every decade. If one quarter of the world's forests were replanted with carbon-eating varieties of the same species, the forests would be preserved as ecological resources and as habitats for wildlife, and the carbon dioxide in the atmosphere would be reduced by half in about fifty years.

It is likely that biotechnology will dominate our lives and our economic activities during the second half of the twenty-first century, just as computer technology dominated our lives and our economy during the second half of the twentieth. Biotechnology could be a great equalizer, spreading wealth over the world wherever there is land and air and water and sunlight. This has nothing to do with the misguided efforts that are now being made to reduce carbon emissions by growing corn and converting it into ethanol fuel. The ethanol program fails to reduce emissions and incidentally hurts poor people all over the world by raising the price of food. After we have mastered biotechnology, the rules of the climate game will be radically changed. In a world economy based on biotechnology, some low-cost and environmentally benign backstop to carbon emissions is likely to become a reality.

Well lets get on that then!

But seriously. As with most subjects I blog on I am the furthest thing from an expert on either Global Warming or certainly biotechnology, but my first question with all of this is I think the most obvious one. And that would have to be how does one account for - within this plan of replanting a quarter of the planet's forests with special super carbon-eating biogenetically engineered trees - the law of unintended consequences. (Which I guess being unintended doesn't fit easily into anyone's methodology) Once we plant and grow all these trees how can be sure they will do everything they're supposed to do and nothing else - like, I don't know, take over the entire ecosystem! But seriously. If we couldn't account for the actual law of unintended consequences, I think the perception of a possible, potential unintended consequence might be enough to stop any plan like this in its tracks. Which speaks to a larger, looming issue within this Very Big Issue - which is reconciling biotechnology - altering the genome and the genetic structure of plants and even I suppose potentially actual creatures themselves, even humans I guess - with the so-called 'environmental' movement. For all I know Dyson's plan might be the most brilliant one going and totally plausible in, as he says,like - fifty years. And by then who knows what state the planet is going to be in and how people are going to think and what their attitudes are going to be about biotechnology, but I think we can safely say that for now, in our time, one of the basic tenants of the so-called 'environmental movement' (and I do feel the need to keep qualifying it with 'so-called' because I hate to generalize and I don't think anything this large and amorphous can be easily defined) is a profound suspicion with scientific and technological hubris. (Though I suppose one person's hubris is another person's genius) Environmentalism, as I understand it, often speaks to and of learning to live within our basic nature and ecosystem and not outside it. That venturing 'outside of nature' has in fact been one of our grand collective failings as far as the 'environment' is concerned. That we are part of nature and not above it, and subsequently we need to respect it more and fuck with it a whole lot less. And in this sense there are still many potential carbon reducing technologies that could be rolled out in a far larger scale than at present which still incorporate this basic world view - Solar power, obviously, being the first one the leaps to mind. As Jeffery Sachs wrote recently in The Guardian:

The most promising technology in the long term is solar power. The total solar radiation hitting the planet is about 1,000 times the world's commercial energy use. This means that even a small part of the earth's land surface, notably in desert regions, which receive massive solar radiation, can supply large amounts of the electricity for much of the rest of the world.

For example, solar power plants in America's Mojave desert could supply more than half of the country's electricity needs. Solar power plants in northern Africa could supply power to western Europe. And solar power plants in the Sahel region of Africa, just south of the vast Sahara, could supply power to much of west, east, and central Africa.

But what of Dyson's basic suggestion of larger emphasis on the possible uses of biotechnology? Using our human intelligence to alter some of our most basic eco-systems in order to correct and roll back some of the environmental damage we've created and accumulated?

I think it will be met with much skepticism (if it is in fact met - at all) because it challenges some of the most basic assumptions of the religion of contemporary environmentalism. i.e. that we are where we are because we have sinned, and now the only way forward is to repent. Accept the base corruption of our nature, and our past, see the light, seize the day and now totally change our ways, and reengineer some of the most basic systems of our economy - (of which and in which we are all complicit) - making them more sustainable and carbon-neutral. I think its a general (there I go again) skepticism that greets all possible solutions to the crisis of Global Warming that seem, I don't know, too techno-positive. And let me be clear I do think we have "sinned" and continue to "sin" in all kinds of ways. We are a lot smarter, and certainly have the potential to be a lot smarter than we presently act and we shouldn't deny it and pretend otherwise. But I do think 'environmentalism' is very much, behaves, exits very much like a kind of contemporary religion (though one more firmly based on fact and in science than most other religions.). And I'm not suggesting that that's a bad thing. It may in fact be the best thing. The only thing. Its a point that Dyson concedes at the end of his review:

All the books that I have seen about the science and economics of global warming, including the two books under review, miss the main point. The main point is religious rather than scientific. There is a worldwide secular religion which we may call environmentalism, holding that we are stewards of the earth, that despoiling the planet with waste products of our luxurious living is a sin, and that the path of righteousness is to live as frugally as possible. The ethics of environmentalism are being taught to children in kindergartens, schools, and colleges all over the world.

Environmentalism has replaced socialism as the leading secular religion. And the ethics of environmentalism are fundamentally sound. Scientists and economists can agree with Buddhist monks and Christian activists that ruthless destruction of natural habitats is evil and careful preservation of birds and butterflies is good. The worldwide community of environmentalists—most of whom are not scientists—holds the moral high ground, and is guiding human societies toward a hopeful future. Environmentalism, as a religion of hope and respect for nature, is here to stay. This is a religion that we can all share, whether or not we believe that global warming is harmful.

Though it has its aspects and cringe-worthy examples of fashionable hype and preening superficiality like everything else in this world - how can it go away now? Environmentalism? We are stuck with it now like we are stuck with the planet itself, complete with its brewing atmosphere. And we are stuck with it for the fundamental reasons that every one knows. Unlike Socialism, it can't go away. (Though I know many people who would argue the need and the necessity for Socialism has never gone away. What can I tell you. I hang with a bad crowd.)

Only through a massive exercise of collective denial, I suppose. Which I guess, isn't totally out of the realm of possibility.

The extent of the hype cycle's corruption of our minds can be measured by the frequency with which you hear people complaining that environmentalism has grown so fashionable, so chic, so trendy. Try to imagine a similar complaint from another political era: "I was totally into democracy—before they extended the franchise. I was all about socialism—but it became so working class."